On Board Diagnostic (OBD), Operation

On Board Diagnostic (OBD), operation
The Multitronic 01J constantly variable automatic transmission is controlled electronically/hydraulically.

The Transmission Control Module (TCM) receives information from components which influence the shifts. Based on this information, the control module activates the applicable proportioning valves in the valve body. The three proportioning valves regulate the fluid pressure generated by the ATF pump.

Proportioning valve 1 regulates the opening and closing of the clutches or brakes respectively.

Proportioning valve 2 controls the transmission ratio between the two disc sets, depending on driving conditions, i.e. it regulates the pressures on the adjusting cylinders of the two disc sets and keeps the chain at a constant tension.

Proportioning valve 3 regulates ATF cooling of the transmission.
A more precise description and operation of the individual valves can be found in
Refer to Self-study Program Course No. 951103, Variable Automatic Transmission, Multitonic 01J